<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>首页</title>
</head>
<style>
    .box{
        width:100px;
        height: 100px;
        background: red;
    }
</style>
<body>
    <div class="box"></div>
</body>
</html>